how do i convert a file + offset in ext4 to a block device number?

Question

I am writing a block device driver and I have mounted ext4 file system on it. When i run fio verify on a file from ext4 , I get a verify error.

How does one convert the file,offset in ext4 to a block device number?

Answer 1

This is answered over on https://serverfault.com/questions/309641/how-can-i-find-out-where-a-file-is-physically-located-on-the-disk-block-numbers which says debugfs can be used for this purpose. For example:

debugfs -R "stat ~/myfile" /dev/sda1